1. Field of the Invention
The present invention relates to an apparatus for synthesizing carbon nanotubes, and more particularly, to an apparatus for synthesizing carbon nanotubes, which discharges non-reacted gas for synthesizing carbon nanotubes to an exhaustion unit, and includes a blocking unit that blocks the discharge of synthesized carbon nanotubes and catalysts.
2. Description of the Related Art
Carbon nanotubes (CNT) is a carbon allotrope consisting of carbons existing on earth. One atom of carbon is coupled with another atom of carbon in a honeycomb pattern to form a tube shape, and the diameter of the tube is only a few nanometers. The carbon nanotubes (CNT) has good mechanical features, outstanding field-emitting features and highly-efficient hydrogen storage medium features, and is known as a promising new material.
Such carbon nanotubes can be manufactured by an advanced synthesizing technology, and some examples of the technology are the arc-discharge, laser vaporization, plasma enhanced chemical vapor deposition (PECVD), thermal chemical vapor deposition, electrolysis, and flame synthesis.
Generally, the process of manufacturing carbon nanotubes can be divided into the process of applying catalysts on a board where carbon nanotubes are synthesized, the process of synthesizing carbon nanotubes by inserting the board, where the catalysts have been applied, into a reaction tube and making the reaction gas react to the applied catalysts, and the process of returning carbon nanotubes that have been synthesized on the board.
The apparatus for synthesizing carbon nanotubes can be divided into a horizontal type and a vertical type depending on the form in which the reaction tube has been disposed. The apparatus for synthesizing carbon nanotubes with a vertical-type reaction tube is under active development due to the advantages of the size of the reaction tube, the consumption of reaction gas, and efficiency.
Further, the types of carbon nanotubes are divided into single-walled nanotubes (SWNT) and multi-walled nanotubes (MWNT) depending on the number of combinations that form the wall for forming the tube, and especially a bundle type where single-walled nanotubes are combined is called a robe nanotubes. The type of such carbon nanotubes can be determined according to the form of the catalyst reacting to reaction gas, i.e., the shape of the catalysts density, and the particle size, and the types of the used catalyst can be determined according to the method of producing the catalyst.
In a vertical-type carbon nanotubes synthesizer, the catalyst is positioned inside the reaction tube, and by spraying the reaction gas to the catalyst, the catalyst floats inside the reaction tube by the spraying pressure and the synthesis is done. Here, an exhaustion unit that discharges the remaining reaction gas and the remaining gas is positioned on the upper side of the reaction tube, and a blocking unit is formed so that only the reaction gas is discharged through the exhaustion unit, and the synthesized carbon nanotubes and the catalyst are not exhausted.
Here, there is a need for providing a blocking unit that effectively discharges the reaction gas to the outside, prevents the synthesized carbon nanotubes and the catalyst from being discharged, and prevents the carbon nanotubes and the catalyst from being piled up. It is because the productivity can be improved as the synthesized carbon nanotubes and the catalyst, which have not been discharged to the outside by the blocking unit, are synthesized inside the reaction tube again.